I made a royal hash of my bottom job - I didn't get all the gelcoat off the bottom before applying the new fiberglass tape. I was using a 5" orbital sander and it just didn't seem to make any headway with 80 grit paper on the gelcoat.

So two questions:

1) Any recommendations for what kind of sander will do a better job getting the gelcoat off? (I also need to sand off dripped polyester resin). Please suggest specific models - I need something with more guts I'm guessing.2) Do I need to remove the fiberglass tape I applied over partially-removed gelcoat? Or do I just leave it on and add more over it?

I made a royal hash of my bottom job - I didn't get all the gelcoat off the bottom before applying the new fiberglass tape. I was using a 5" orbital sander and it just didn't seem to make any headway with 80 grit paper on the gelcoat.

So two questions:

1) Any recommendations for what kind of sander will do a better job getting the gelcoat off? (I also need to sand off dripped polyester resin). Please suggest specific models - I need something with more guts I'm guessing.2) Do I need to remove the fiberglass tape I applied over partially-removed gelcoat? Or do I just leave it on and add more over it?

Best choice is an air-powered one - that way the dust doesn't eat up the brushes in the electric motor.

Pros use a angle sander:But you've got to be really gentle with it. It will tear up the boat if you're not careful.

Durablocks with PSA to get close enough for final squeegee coat, and sanding with wet-or-dry to get to the point that it's ready for spraying gelcoat. Durablocks come up to about 3 feet long. PSA sandpaper comes in rolls, so you cut length to fit whichever block you use. The Durablocks flex some, but not enough to allow digging dips like you can by hand. http://www.autobodytoolmart.com/dura-bl ... 11890.aspx

I made a royal hash of my bottom job - I didn't get all the gelcoat off the bottom before applying the new fiberglass tape. I was using a 5" orbital sander and it just didn't seem to make any headway with 80 grit paper on the gelcoat.

So two questions:

1) Any recommendations for what kind of sander will do a better job getting the gelcoat off? (I also need to sand off dripped polyester resin). Please suggest specific models - I need something with more guts I'm guessing.2) Do I need to remove the fiberglass tape I applied over partially-removed gelcoat? Or do I just leave it on and add more over it?

Best choice is an air-powered one - that way the dust doesn't eat up the brushes in the electric motor.

Pros use a angle sander:But you've got to be really gentle with it. It will tear up the boat if you're not careful.

Hi Matt, I'm wondering what the difference is between the angle sander in your picture and what I have pictured below. I used this Makita GV5010 5" disc sander last summer when I painted my house and I have to say it is quite possibly the best tool I have ever purchased. It is extremely light weight, has a semi-flexible backing pad and can be used with discs ranging from 20 grit all the way up to 120 grit or more. I agree you would want to be extremely careful using it on a boat. That said, I was surprised by the amount of control I had using this sander my house (I thought it would be digging in and jumping around all over the place but that wasn't the case). Anyways, a fantastic tool. The 50 and 80 grit discs were magic on my house.